Explosive package



Nov. 29, 1938. N. G. JOHNSON 2,138,603

EXPLOSIVE PACKAGE Filed Oct. 6, 1956 /V0l7776/77 GJo/zzfion IINVENTOR.

BY q% w A TTORNEY Patented Nov. 29, 1938 res EWLOSIVE PACKAGE Norman G.Johnson, Wenonah, N. 3., assignor to E. I. du Pont de Nemours & Company,Wilmington, DeL, a corporation of Delaware Application October 6,

5 Claims.

The present invention relates to a. new and improved explosive package,and more particularly to such a package whereby efficiency and safety incharging substantially vertical bore holes are 5 assured.

Although unusual precautions are necessary in any form of activity inwhich explosives are handled, safety considerations are of particularimportance in the art of quarrying. In the 10 blasting down of rock foruse in cement manufacture, road construction and other such purposes,and in stripping operations generally, it is customary to employ verylarge amounts of high strength explosives in one blast.

20,000 pounds of explosive at one time in quarry blasting. The explosiveis loaded into vertical bore holes, generally known as well drill holes.'Under such conditions of blasting, where very 20 large amounts ofexplosive must be on hand during the loading operations, it isespecially desirable that every safety precaution be observed.

It is a common practice in the art to tie the explosive cartridge withtwine, in much the same 55 fashion that a store clerk ties a parcel. Thelowering rope is then attached to said twine, and the package loweredinto the bore hole, which is commonly from 30 to 100 feetdeep.Frequently, the package becomes untied, or the loop slips 011, Iallowing the cartridge to fall to the bottom of the hole. Since thecartridges commonly used in quarry blasting may be in sizes up to 7x 24.inches, weighing perhaps 50 pounds, the undesirability of dropping suchcartridges will be very apparent. If such a slip occurs near the top ofthe hole the drop is sometimes sufficient to initiate whatever explosiveis already in the hole, as well as that on the surface near the mouth ofthe hole in preparation for charging. If such 0 premature explosionoccurs, a major disaster may result.

Even if an explosive less sensitive to shock is employed, it isundesirable to drop the cartridge, for the wrapper will be broken, andthe powder 5 scattered about the bottom of thehole, which is usuallydamp and often partially filled with water. Since the type of explosivecommonly used for blasting has little water resistance, a misfire withattendant dangers may result. In

1 addition, jagged projections often occur in the hole, which obstructthe passage of the falling cartridge before it has reached the bottom.In such a situation it is especially desirable to have the cartridgeunder sure control, in order that i it may be withdrawn to permit safeintroduc- It is comj 15 mon, for example, to shoot as much as 10,000 to1936, Serial No. 104,195

tion of tools for clearing away the obstruction.

A further attempt at controlled lowering is involved in the well knownpractice of driving a wooden peg into the end of the cartridge,attaching the'rope to the end of the peg, and sus- 5 pending thecartridge in the hole, withdrawing the peg with a sharp pull when thecartridge reaches the bottom of the hole. It is recognized that thispractice is likewise unsafe, for the peg may pull out prematurely, ifthe friction is not sufiicient to hold it in the explosive.

The chief object of the present invention is a new and improvedexplosive package. A further object is such an explosive package thatsafety in charging vertical holes is assured. Another object is a safemethod for charging vertical holes with blasting explosive. Additionalobjects will be.disclosed as the invention is further described.

The foregoing objects are attained by application of the principles ofmy invention, according to which the explosive cartridge is completelyencased in a web of netting or similar material. Any suitable means maybe employed for attaching a lowering device to the end of this explosivepackage, whereby an approximately vertical suspension is obtained. Thelowering means will be desirably detachably fastened to the package inorder to permit the former to be withdrawn after the package has reachedthe bottom of the hole.

The method according to my invention presents marked advantages over thepractices of the art in that the cartridge will not fall and.- break inawet bore hole, nor become jammed in the bore hole by falling into anobstruction therein. At all times during its descent into the hole, the'cartridge will be under control, and may be readily withdrawn to permitthe safe entrance of tools for the purpose of removing obstructions. Amore nearlyvertical suspension is 40 possible with the netting than bythe driven peg method, or by tying the cartridge like a. parcel. Nordoes the net consist of suflicient material to alter the oxygen balanceof the cartridge, as would be the case where a thick wrapper was usedfor the same purpose.

. Figure I of the drawing is a view in elevation of a preformedtubular-web. Figure II is a similar view witha closure at one end oftheweb, and

with means for attaching a lowering device. Figum HI is a view inelevation of the package before final closure. Figure IV is an elevationof the ,completed package. Figure V is an elevation of the explosivepackage with attached lowering means. Figure VIis an elevation of theexplo- 5 2 sive package including a preformed sack of netting.

Referring to Figure I, I prefer to employ a preformed tubular web l ofthe type depicted, for carrying out the principles of my invention.These tubes may be obtained many thousand feet in length, and cut intosuitable lengthsat the explosive plant. I then prefer to draw the web 8,

to a closure at one end, as shown in Figure 11, by

means of the knot 2, and attach the ring 3 of a non-sparking metal. Thebag is thus formed at a location apart from the dynamite area of theplant, and is then transported to the dynamite line, and the cartridge lis encased therein, as shown in Figure III. A final closure is made bythe knot 5, as shown in Figure IV, giving a finished safe explosivepackage, which may be suspended detachably from a lowering means bypassing the hook 6 of Figure V through the ring 3. Upon reaching thebottom of the bore hole, the hook may be freed from the ring byproviding suitable slack in the lowering means. The package of Figure VIdiffers from that of Figure IV only in the feature that it discloses anentirely preformed sack of netting with woven closure 1 at the one end.i

It is to be understood that the foregoing illustrations representpreferred embodiments of my invention, and are not intended to limit thescope thereof It will be seen from the foregoing description of myinvention that a new and improved explosive package has been produced,which packageis extremely desirable from the standpoint of safety andconvenience in charging vertical drill holes, or bore holes, in quarryblasting and similar operations. With the use of this packageinconjunction with suitable lowering means an approximately verticalsuspension is obtained, and the cartridge is always under control duringthe lowering process. The use of the net offers the additional advantageover the tying method of the art, that the web of netting may be sentpreformed to the dynamite line, so that, where six men were formerlynecessary in the tying operation, the new packages may be formed by twomen in the same quantities in a.v shorter time, with much less handling.As a result the number of greases employees present, exposed in themanufacturing operations, is greatly reduced, with correspondingincrease in the safety of the operation.

Although I prefer to employ a netting material in the nature of fishnet, with mesh of any suitthat my invention be limited only accordingtothe following patent claims:

I claim:

1. An explosive package comprising an explosive cartridge, 9. web ofnetting surrounding and enclosing "said cartridge, and means including aportion of said netting for attaching a lowering device to said package.

2. An ex'plosive package comprising an explosive cartridge, a web ofnetting surrounding and enclosing said cartridge, and a rigid eyeletattached to said netting whereby lowering means may be aflixed thereto.

3. An explosive package comprising an explosive' cartridge, a web ofnetting surrounding and enclosing said cartridge, and a metal ringattached to. said netting whereby controlled lowering of said packagemay be effected.

4. An explosive package comprising an expl'osive cartridge, a preformedsack of netting surrounding and enclosing said cartridge, and meansincluding a portion ofsaid netting for attaching a lowering device tosaid package.-

'5. An explosive package comprising an explosive cartridge, a tubularweb of netting surrounding and enclosing said cartridge, said tubularweb being gathered together and knotted at each end of said cartridge,and means including one of said knotted portions of said web forattaching a lowering device to said package.

NORMAN G. JOHNSON.

